I forced myself to sleep on my back the entire night last night because I normally can't maintain this position for more than four hours and always switch to my stomach. But by staying on my back, I learned that the back of my neck gets numb, which probably is the reason that I switch to my stomach and have so many sleep disturbances throughout the night. Is it possible that TOS symptoms include back of the neck numbness or even just neck numbness in general when laying down for extended periods of time such as sleeping? Has anyone had TOS surgery and noticed an improvement from this?

I don't get numb when sleeping, but I get numbness all over my neck, chest and shoulders if I try to stretch the scalenes. You could be stretching the nerves when sleeping on your back.

What kind of pillow do you use?

I'm currently using a low profile foam pillow. It's the only one I can use for back sleeping and I've been through about 20 pillows over three years.

A contoured one for the neck curves, or more of a flat standard foam type?

I have best luck with the contoured style.

Same here. I have a closet full of pillows.
I ended up using an orthopedic pillow like this one: http://www.amazon.com/Core-Tri-Core-...words=core+200

I wouldn't call it very comfortable and it took some time to get used to, but anything else gives me neck pain (no numbness though).

Does TOS cause muscle tightness in the neck?